JP7089159B2 - Light emitting device - Google Patents

Description

The present invention relates to a light emitting device.

For example, Patent Document 1 describes a light emitting device having a substrate, an LED chip mounted on the substrate, a phosphor layer above the LED chip, and a dam material (first reflecting member) surrounding the LED chip. Has been done.

Japanese Unexamined Patent Publication No. 2014-072213

An object of the present invention is to provide a light emitting device capable of improving the bonding strength between a substrate and a first reflective member.

The light emitting device according to one aspect of the present invention has an upper surface, a lower surface located on the opposite side of the upper surface, a side surface located between the upper surface and the lower surface, and openings in the upper surface and the side surface of the upper surface. A substrate having a base material having a recess surrounding the outer periphery, a first wiring arranged on the upper surface thereof, and light emitting light electrically connected to the first wiring and placed on the first wiring. A first light emitting element having a peak wavelength of 430 nm or more and less than 490 nm and a second light emitting element having a peak wavelength of 490 nm or more and 570 nm or less, which is electrically connected to the first wiring and placed on the first wiring. A light guide member that covers the first light emitting element, the second light emitting element, and the upper surface and is separated from the recess, and the light guide that is arranged in the recess and surrounds the upper surface and the light guide member. An annular first reflective member in contact with the member is provided, and at least a part of the side surface of the base material and at least a part of the outer surface of the first reflective member are flush with each other.

According to the light emitting device of the embodiment according to the present invention, it is possible to provide a light emitting device capable of improving the bonding strength between the substrate and the first reflective member.

FIG. 1A is a schematic perspective view of the light emitting device according to the first embodiment. FIG. 1B is a schematic perspective view of the light emitting device according to the first embodiment. FIG. 2A is a schematic top view of the light emitting device according to the first embodiment. FIG. 2B is a schematic cross-sectional view taken along the line IIB-IIB of FIG. 2A. FIG. 3 is a schematic top view of the substrate according to the first embodiment. It is schematic cross-sectional view of the modification of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic side view of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic side view of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic bottom view of the light emitting device which concerns on Embodiment 1. FIG. It is schematic cross-sectional view of the modification of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic top view of the modification of the light emitting device which concerns on Embodiment 2. FIG. FIG. 10 is a schematic cross-sectional view taken along the line XA-XA of FIG. It is a schematic bottom view of the light emitting device which concerns on Embodiment 2. FIG. It is a schematic sectional drawing of the modification of the light emitting device which concerns on Embodiment 2. FIG.

Hereinafter, embodiments of the invention will be described with reference to the drawings as appropriate. However, the light emitting device described below is for embodying the technical idea of the present invention, and the present invention is not limited to the following unless otherwise specified. Further, the contents described in one embodiment can be applied to other embodiments and modifications. Further, the size and positional relationship of the members shown in the drawings may be exaggerated in order to clarify the explanation.

<Embodiment 1>
The light emitting devices 1000A, 1000B, 1000C according to the first embodiment of the present invention will be described with reference to FIGS. 1A to 8. The light emitting device 1000A includes a substrate 10, a first light emitting element 20A, a second light emitting element 20B, a light guide member 50, and a first reflecting member 40. The substrate 10 includes a base material 11 and a first wiring 12. The base material 11 has an upper surface 111, a lower surface 112 located on the opposite side of the upper surface 111, and a side surface 113 located between the upper surface 111 and the lower surface 112. Further, the base material 11 is provided with a recess 115 that opens in the upper surface 111 of the base material 11 and the side surface 113 of the base material 11 and surrounds the outer periphery of the upper surface 111 of the base material 11. The first wiring 12 is arranged on the upper surface 111 of the base material 11. The first light emitting element 20A is electrically connected to the first wiring 12 and is mounted on the first wiring 12. The emission peak wavelength of the first light emitting element 20A is 430 nm or more and less than 490 nm. The second light emitting element 20B is electrically connected to the first wiring 12 and is placed on the first wiring 12. The emission peak wavelength of the second light emitting element 20B is 490 nm or more and 570 nm or less. The light guide member 50 covers the first light emitting element 20A, the second light emitting element 20B, and the upper surface 111 of the base material 11, and is separated from the recess 115 of the base material 11. The first reflective member 40 is annular in the top view, is arranged in the recess 115 of the base material 11, and surrounds the upper surface 111 of the base material 11 and the light guide member 50. Further, the first reflective member 40 is in contact with the light guide member 50. At least a part of the side surface 113 of the base material 11 and at least a part of the outer surface 412 of the first reflective member 40 are flush with each other. In addition, in this specification, "floating" means that a fluctuation of about ± 5 μm is allowed.

Further, the substrate 10 may include a recess 16 that opens in the lower surface 112 of the base material 11 and the side surface 113 of the base material 11. Further, the substrate 10 may include a second wiring 13, a third wiring 14, and a via 15. The second wiring 13 is arranged on the lower surface 112 of the base material 11. The third wiring 14 covers the inner wall of the recess 16 of the base material 11 and is electrically connected to the second wiring 13. The via 15 is provided in a hole penetrating from the upper surface 111 to the lower surface 112 of the base material 11, and electrically connects the first wiring 12 and the second wiring 13.

The first reflective member 40 is arranged in the recess 115 of the base material 11. As a result, the contact area between the base material 11 and the first reflective member 40 increases, so that the bonding strength between the substrate 10 and the first reflective member 40 can be improved. The light guide member is separated from the recess of the base material. As a result, the contact area between the base material 11 and the first reflective member 40 increases, so that the bonding strength between the substrate 10 and the first reflective member 40 can be improved. The first reflective member 40 is integrally arranged on the outer periphery of the base material 11.

As shown in FIG. 3, the recess 115 of the base material 11 is arranged on the outer periphery of the base material 11. That is, the thickness of the outer periphery of the base material 11 is thinner than the thickness of the base material at the position where the first light emitting element and the second light emitting element are placed. The thickness of the base material means the thickness of the base material in the Z direction. The depth of the recess in the Z direction is preferably 5 μm or more and 80 μm or less. When the depth of the recess is 5 μm or more, the contact area between the base material 11 and the first reflective member 40 can be increased. When the depth of the recess is 80 μm or less, the strength of the base material 11 is improved. The width of the recess is preferably 10 μm or more and 50 μm or less. When the width of the recess is 10 μm or more, the contact area between the base material 11 and the first reflective member 40 can be increased. When the width of the recess is 50 μm or less, the strength of the base material 11 is improved. In the present specification, the width of the recess refers to the shortest distance from the inner circumference to the outer circumference of the recess in a top view. In the X direction, it is preferable that the width of the concave portion of the portion where the first light emitting element and / or the second light emitting element is located is the same. In the Y direction, it is preferable that the width of the recess in the portion where the first light emitting element and / or the second light emitting element is located is the same. By doing so, it becomes easy to design the width of the first reflective member in the X direction and / or the Y direction to be thin, so that the light emitting device can be miniaturized. The recess can be formed by blade dicing, laser dicing, or the like. In the present specification, the width of the first reflective member refers to the shortest distance from the inner surface 411 to the outer surface 412 of the first reflective member in a top view.

The light emitting device 1000A has a first light emitting element having a light emitting peak wavelength in the range of 430 nm or more and less than 490 nm (wavelength range in the blue region), and a light emitting peak wavelength in the range of 490 nm or more and 570 nm or less (wavelength range in the green region). By providing the two light emitting elements, the color playability of the light emitting device can be improved. For example, as shown in FIG. 2B, the light emitting device 1000A may include a first light emitting element 20A, a second light emitting element 20B, and a third light emitting element 20C. When the first light emitting element 20A, the second light emitting element 20B, and the third light emitting element 20C are arranged in this order in the X direction, the emission peak wavelength of the first light emitting element 20A and the third light emitting element 20C. It is preferable that the emission peak wavelength is the same. By doing so, for example, when the output of the first light emitting element 20A is insufficient, it can be supplemented by the third light emitting element 20C. Further, the second light emitting element 20B having a light emitting peak wavelength different from the light emitting peak wavelength of the first light emitting element 20A and the light emitting peak wavelength of the third light emitting element 20C is located between the first light emitting element 20A and the third light emitting element 20C. By doing so, the color rendering property of the light emitting device is improved, and the color unevenness is reduced as compared with the case where the first light emitting element 20A, the third light emitting element 20C, and the second light emitting element 20B are arranged in order. Can be done. When the second light emitting element 20B, the first light emitting element 20A, and the third light emitting element 20C are arranged in this order in the X direction, the emission peak wavelength of the second light emitting element 20B and the third light emitting element are arranged. It is preferable that the emission peak wavelength of 20C is the same. By doing so, for example, when the output of the second light emitting element 20B is insufficient, it can be supplemented by the third light emitting element 20C. In the present specification, the same as the emission peak wavelength means that a fluctuation of about ± 10 nm is allowed.

The first light emitting element 20A includes a first element light extraction surface 201A, a first element electrode forming surface 203A on the opposite side of the first element light extraction surface, a first element light extraction surface 201A, and a first element electrode forming surface. A first element side surface 202A between the 203A and a pair of first element electrodes 21A and 22A are provided on the first element electrode forming surface 203A. The first light emitting element 20A includes at least the first element semiconductor laminate 23A, and the first element semiconductor laminate 23A is provided with a pair of first element electrodes 21A and 22A. In the present embodiment, the first light emitting element 20A has the first element substrate 24A, but the first element substrate 24A may be removed. Similar to the first light emitting element 20A, the second light emitting element 20B includes a second element light extraction surface 201B, a second element electrode forming surface 203B, a second element side surface 202B, and a pair of second element electrodes 21B and 22B. And. The second light emitting device 20B includes at least the second element semiconductor laminate 23B. In the present embodiment, the second light emitting element 20A has the second element substrate 24B, but the second element substrate 24B may be removed. Similar to the first light emitting element 20A, the third light emitting element 20C comprises a third element light extraction surface 201C, a third element electrode forming surface 203C, a third element side surface 202C, and a pair of third element electrodes. Be prepared. The third light emitting device 20C includes at least a third element semiconductor laminate. In the present embodiment, the third light emitting element 20C has the third element substrate, but the third element substrate may be removed. The light extraction surface 201A of the first element may be referred to as the upper surface of the first light emitting element. The second element light extraction surface 201B may be referred to as the upper surface of the second light emitting element. The third element light extraction surface 201C may be referred to as the upper surface of the third light emitting element. The first element electrode forming surface 203A may be referred to as a lower surface of the first light emitting element. The second element electrode forming surface 203B may be referred to as a lower surface of the second light emitting element. The third element electrode forming surface 203C may be referred to as a lower surface of the third light emitting element. Further, the first light emitting element, the second light emitting element and / or the third light emitting element may be referred to as a light emitting element 20.

As shown in FIG. 2A, when the first element light extraction surface and the second element light extraction surface are rectangular in top view, the short side of the first element light extraction surface and the short side of the second element light extraction surface are short. It is preferable that the sides face each other. By doing so, the light emitting device 1000A can be made thinner in the Y direction. When the second element light extraction surface 201B and the third element light extraction surface 201C are rectangular, it is preferable that the short side of the second element light extraction surface and the short side of the third element light extraction surface face each other. .. By doing so, the light emitting device 1000A can be made thinner in the Y direction.

As shown in FIG. 2B, it is preferable that the first wiring 12 is provided with a convex portion 121 at a position corresponding to the pair of first element electrodes 21A and 22A of the first light emitting element 20A. In other words, it is preferable that the first wiring 12 has a convex portion 121 at a position where it overlaps with the first element electrodes 21A and 22A in the top view. Since the first wiring 12 includes the convex portion 121, when the first wiring 12 and the first element electrodes 21A and 22A are connected via the conductive adhesive member 60, the first light emitting element and the first light emitting element due to the self-alignment effect. Alignment with the substrate can be easily performed. The thickness of the convex portion 121 in the Z direction is preferably 10 μm or more and 30 μm or less. Similarly, when the light emitting device includes the second light emitting element 20B and / or the third light emitting element 20C, the first wiring 12 may have a convex portion 121 at a position corresponding to the pair of electrodes of the light emitting element. preferable. By doing so, it is possible to easily align the light emitting element and the substrate by the self-alignment effect. The width of the convex portion 121 in the X direction and / or the Y direction may be appropriately changed depending on the size of the electrodes of the opposing light emitting elements. For example, the width of the convex portion 121 corresponding to the first element electrodes 21A and 22A of the first light emitting element in the X direction is the width of the convex portion 121 corresponding to the second element electrodes 21B and 22B of the second light emitting element in the X direction. May be shorter than.

The light guide member 50 covers the first light emitting element, the second light emitting element, and the upper surface 111 of the base material 11. By covering the light guide member 50 with the first light emitting element and the second light emitting element, the first light emitting element and the second light emitting element can be protected from external stress. When the light emitting device includes a third light emitting element, the light guide member covers the third light emitting element. The light guide member 50 preferably covers the upper surface of the light emitting element 20 and the side surface of the light emitting element 20. The light guide member 50 has a higher transmittance of light from the light emitting element 20 than the first reflecting member 40. Therefore, when the light guide member 50 covers the upper surface of the light emitting element and the side surface of the light emitting element, it becomes easy to take out the light from the light emitting element through the light guide member 50 to the outside of the light emitting device. This makes it possible to improve the light extraction efficiency of the light emitting device.

The light guide member may include a wavelength conversion member. By doing so, the color adjustment of the light emitting device becomes easy. The wavelength conversion member is a member that absorbs at least a part of the primary light emitted by the light emitting element 20 and emits secondary light having a wavelength different from that of the primary light. The wavelength conversion member may be uniformly dispersed in the light guide member, or the wavelength conversion member may be unevenly distributed in the vicinity of the substrate rather than the upper surface of the light guide member. Examples of the wavelength conversion member included in the light guide member include a wavelength conversion member that emits green light having a emission peak wavelength of 490 nm or more and 570 nm or less, a wavelength conversion member that emits red light having an emission peak wavelength of 610 nm or more and 750 nm or less. Can be used. The wavelength conversion member contained in the light guide member may be of one type or may contain a plurality of types. For example, the light guide member may include a wavelength conversion member that emits green light and a wavelength conversion member that emits red light. Examples of the wavelength conversion member that emits green light include a β-sialon-based phosphor (for example, Si _6-z Al _z O _z N _8-z : Eu (0 <z <4.2)). Examples of the member include a phosphor of manganese _- activated potassium fluoride fluorinated (for example, K2 SiF ₆ : Mn).

The light emitting device 1000A preferably includes a translucent member that covers the upper surface of the first light emitting element and the upper surface of the second light emitting element via the light guide member. By covering the upper surface of the first light emitting element and the upper surface of the second light emitting element with the translucent member, the first light emitting element and the second light emitting element can be protected from external stress. When the light emitting device includes the third light emitting element, the translucent member covers the upper surface of the third light emitting element via the light guide member. When the light emitting device includes the translucent member 30, it is preferable that the side surface of the translucent member is covered with the first reflective member 40. By doing so, it is possible to obtain a light emitting device having a high contrast between the light emitting region and the non-light emitting region and having good "parting ability".

The translucent member 30 may include a wavelength conversion member. By doing so, the color adjustment of the light emitting device becomes easy. The emission peak wavelength of the wavelength conversion member contained in the translucent member is preferably 610 nm or more and 750 nm or less (wavelength range in the red region). Since the emission peak wavelength of the first light emitting element is in the wavelength range of the blue region and the emission peak wavelength of the second light emitting element is in the wavelength range of the green region, the emission peak wavelength of the wavelength conversion member contained in the translucent member is Being in the wavelength range of the red region improves the color playability of the light emitting device. The wavelength conversion member contained in the translucent member may be one kind or may contain a plurality of kinds. For example, a wavelength conversion member that emits green light and a wavelength conversion member that emits red light may be contained in the translucent member. By providing the wavelength conversion member in which the translucent member emits green light, the color adjustment of the light emitting device becomes easy. Examples of the wavelength conversion member that emits green light include a β-sialon-based phosphor (for example, Si _6-z Al _z O _z N _8-z : Eu (0 <z <4.2)). Examples of the member include a phosphor of manganese _- activated potassium fluoride fluorinated (for example, K2 SiF ₆ : Mn).

The wavelength conversion member may be uniformly dispersed in the translucent member, or the wavelength conversion member may be unevenly distributed in the vicinity of the light emitting element rather than the upper surface of the translucent member. By unevenly distributing the wavelength conversion member near the light emitting element rather than the upper surface of the translucent member, the base material of the translucent member also functions as a protective layer even if a moisture-sensitive wavelength conversion member is used. Deterioration of the conversion member can be suppressed. Further, the translucent member may include a layer containing a wavelength conversion member and a layer substantially not containing the wavelength conversion member. In the Z direction, the layer that does not substantially contain the wavelength conversion member is located above the layer that contains the wavelength conversion member. By doing so, the layer that does not substantially contain the wavelength conversion member also functions as a protective layer, so that deterioration of the wavelength conversion member can be suppressed. Examples of the wavelength conversion member that is sensitive to moisture include a manganese-activated potassium fluoride silicate phosphor. The manganese-activated potassium fluoride silicate phosphor is a preferable member from the viewpoint of color reproducibility because it can emit light with a relatively narrow spectral line width. "Substantially containing no wavelength conversion member" means that the wavelength conversion member inevitably mixed is not excluded, and the content of the wavelength conversion member is preferably 0.05% by weight or less.

As shown in FIG. 2B, the translucent member 30 includes a first diffusion layer 31A, a translucent layer 31B arranged on the first diffusion layer 31A, and a wavelength conversion layer 31C arranged on the translucent layer 31B. It is preferable to include a second diffusion layer 31D arranged on the wavelength conversion layer. The first diffusion layer 31A includes a base material and a diffusion member. The translucent layer 31B contains a base material and substantially does not contain a wavelength conversion member and diffuse particles. The wavelength conversion layer 31C includes a base material and a wavelength conversion member. The second diffusion layer 31D includes a base material and a diffusion member. In addition, "substantially free of the wavelength conversion member and the diffusion member" means that the wavelength conversion member and the diffusion member inevitably mixed are not excluded, and the content ratios of the wavelength conversion member and the diffusion member are respectively. Is preferably 0.05% by weight or less. The base materials of the first diffusion layer 31A, the translucent layer 31B, the wavelength conversion layer 31C, and the second diffusion layer 31D may be different materials or may be the same material. Since the base materials of the first diffusion layer 31A, the translucent layer 31B, the wavelength conversion layer 31C, and the second diffusion layer 31D are the same material, the bonding strength of each layer is improved. Examples of the base material of the first diffusion layer 31A, the translucent layer 31B, the wavelength conversion layer 31, and the second diffusion layer 31D include a silicone resin.

When the translucent member includes the first diffusing layer and the second diffusing layer, the light from the first light emitting element and the second light emitting element is diffused by the first diffusing layer and the second diffusing layer. As a result, the light from the first light emitting element and the second light emitting element can be mixed in the translucent member and / or the light guide member, so that the color unevenness of the light emitting device 1000A can be reduced.

By locating the translucent layer between the first diffusion layer and the wavelength conversion layer, it is possible to suppress the peeling of the first diffusion layer and the wavelength conversion layer. By locating a translucent layer that does not substantially contain a wavelength conversion member and diffuse particles between the first diffusion layer and the wavelength conversion layer, the translucent layer acts as an adhesive and becomes the first diffusion layer. It is possible to suppress the peeling of the wavelength conversion layer. The light transmitting layer may be located between the wavelength conversion layer and the second diffusion layer. By doing so, it is possible to suppress peeling between the wavelength conversion layer and the second diffusion layer.

The wavelength conversion layer of the translucent member may be a single layer or a plurality of layers. For example, as in the light emitting device 1000B shown in FIG. 4, even if the translucent member 30 includes the first wavelength conversion layer 311B and the second wavelength conversion layer 312B covering the first wavelength conversion layer 311B. good. The second wavelength conversion layer 312B may directly cover the first wavelength conversion layer 311B, or may cover the first wavelength conversion layer 311B via another layer such as a translucent layer. The first wavelength conversion layer 311B is arranged closer to the upper surface of the first light emitting element and the upper surface of the second light emitting element than the second wavelength conversion layer 312B. The emission peak wavelength of the wavelength conversion member contained in the first wavelength conversion layer 311B is preferably shorter than the emission peak wavelength of the wavelength conversion member contained in the second wavelength conversion layer 312B. By doing so, the wavelength conversion member of the second wavelength conversion layer 312B can be excited by the light from the first wavelength conversion layer excited by the first light emitting element and / or the second light emitting element. As a result, the light from the wavelength conversion member of the second wavelength conversion layer 312B can be increased.

The emission peak wavelength of the wavelength conversion member contained in the first wavelength conversion layer 311B is 500 nm or more and 570 nm or less, and the emission peak wavelength of the wavelength conversion member contained in the second wavelength conversion layer 312B is 610 nm or more and 750 nm or less. It is preferable to have. By doing so, it is possible to obtain a light emitting device having high color rendering properties. For example, a β-sialon-based phosphor is mentioned as a wavelength conversion member contained in the first wavelength conversion layer 311B, and a manganese-activated potassium fluorinated phosphor is mentioned as a wavelength conversion member contained in the second wavelength conversion layer 312B. Be done. When a manganese-activated potassium fluoride silicate phosphor is used as the wavelength conversion member contained in the second wavelength conversion layer 312B, the translucent member 30 is particularly divided into the first wavelength conversion layer 311B and the second wavelength conversion. It is preferably provided with the layer 312B. The phosphor of manganese-activated potassium fluoride silicate tends to cause luminance saturation, but the light from the light emitting element is excessively manganese due to the position of the first wavelength conversion layer 311B between the second wavelength conversion layer 312B and the light emitting element. It is possible to suppress irradiation with the phosphor of activated potassium fluoride silicate. As a result, deterioration of the phosphor of manganese-activated potassium fluoride silicate can be suppressed.

As shown in FIG. 2A, the first reflective member 40 is annular in the top view and surrounds the upper surface of the base material and the light guide member. By surrounding the light guide member, the first reflecting member 40 can reflect the light traveling in the X direction and / or the Y direction from the light emitting element 20 and increase the light traveling in the Z direction. Further, since the first reflective member surrounds the upper surface of the base material, the upper surface of the base material is exposed from the first reflective member, so that the area of the light guide member in the top view can be increased. This makes it possible to improve the light extraction efficiency of the light emitting device. Further, the first reflective member is in contact with the light guide member. As a result, the area of the light guide member in the top view can be increased, so that the light extraction efficiency of the light emitting device can be improved.

As the first reflective member, a member containing a white pigment in the base material can be used. The base material of the first reflective member is preferably the same material as the base material of the translucent member. By doing so, the joint strength between the first reflective member and the translucent member can be improved. Further, it is preferable that the base material of the first reflective member, the base material of the translucent member, and the base material of the light guide material member are the same material. By doing so, it is possible to improve the joint strength of the first reflective member, the translucent member, and the light guide member. Since the base material of the first reflective member and the base material of the light guide member are the same material, the joint strength of the first reflective member, the light guide member, and the substrate can be improved.

In top view, the width of the first reflective member is preferably 10 μm or more and 50 μm or less. Since the width of the first reflective member is 50 μm or less, the light emitting device can be miniaturized. Further, when the width of the first reflecting member is 10 μm or more, it is possible to suppress the light from the light emitting element from passing through the first reflecting member.

In top view, it is preferable that the first reflective member and the recess have the same shape. By doing so, it becomes easy to design the width of the first reflective member in the X direction and / or the Y direction to be thin, so that the light emitting device can be miniaturized. In the present specification, the same shape means that a variation of about ± 5 μm is allowed.

As a method of forming the first reflective member, for example, after forming the first light emitting element, the second light emitting element, and the light guide member covering the upper surface of the base material, a part of the base material and the light guide member are formed by blade dicing. It can be formed by removing and filling the recess formed by removing with the first reflective member.

When the substrate is rectangular, the first reflecting member 40 includes a first reflecting portion 401 on the long side and a second reflecting portion 402 on the short side. For example, the width of the first reflection unit 401 and the width of the second reflection unit 402 may be the same length, and the width of the first reflection unit 401 may be longer than the width of the second reflection unit 402. When the width of the first reflecting portion 401 is longer than the width of the second reflecting portion 402, the strength of the first reflecting portion on the long side can be improved.

At least a part of the side surface 113 of the base material 11 and at least a part of the outer surface 412 of the first reflective member 40 are flush with each other. By doing so, the light emitting device can be miniaturized. As shown in FIGS. 5 and 6, when the substrate is rectangular, the side surface 113 of the base material 11 and the outer surface 412 of the first reflective portion are flush with each other, and the side surface 113 of the base material 11 , It is preferable that the outer surface 412 of the second reflecting portion is flush with each other. By doing so, the light emitting device can be further miniaturized.

When the substrate 10 includes the via 15, the via 15 is preferably circular in the bottom view as shown in FIG. 7. By doing so, it can be easily formed by a drill or the like. When the via 15 has a circular shape in the bottom view, the diameter of the via is preferably 100 μm or more and 150 μm or less. When the diameter of the via is 100 μm or more, the heat dissipation of the light emitting device is improved, and when the diameter of the via is 150 μm or less, the decrease in the strength of the substrate is reduced. In the present specification, the circular shape includes not only a perfect circle but also a shape close to this (for example, an elliptical shape or a shape in which the four corners of a quadrangle are chamfered into a large arc shape).

The via 15 may be configured by filling the through hole of the base material with a conductive material, and as shown in FIG. 2B, the fourth wiring 151 and the fourth wiring 151 and the fourth wiring covering the surface of the through hole of the base material. The area surrounded by the wiring 151 may be provided with a filling member 152 filled. The filling member 152 may be conductive or insulating. It is preferable to use a resin material for the filling member 152. Generally, the resin material before curing has higher fluidity than the metal material before curing, so that it is easy to fill the fourth wiring 151. Therefore, the use of a resin material for the filling member facilitates the manufacture of the substrate. Examples of the resin material that can be easily filled include epoxy resin. When a resin material is used as the filling member, it is preferable to include an additive member in order to reduce the coefficient of linear expansion. By doing so, the difference in the coefficient of linear expansion from the fourth wiring becomes small, so that it is possible to suppress the formation of a gap between the fourth wiring and the filling member due to the heat from the light emitting element. Examples of the additive member include silicon oxide. Further, when a metal material is used for the filling member 152, the heat dissipation can be improved. Further, when the via 15 is configured by filling the through hole of the base material with a conductive material, it is preferable to use a metal material such as Ag or Cu having high thermal conductivity.

When the base material 10 includes dents 16 that open to the lower surface of the base material and the side surfaces of the base material, the number of dents may be one or a plurality. By having a plurality of recesses, the bonding strength between the light emitting device 1000A and the mounting substrate can be improved. Even in the top light emitting type (top view type) in which the light emitting device 1000A mounts the lower surface 112 of the base material 11 and the mounting substrate facing each other, the side surface 113 of the base material 11 and the mounting substrate face each other for mounting. Even in the side light emitting type (side view type), the bonding strength with the mounting substrate can be improved by increasing the volume of the bonding member. The bonding strength between the light emitting device 1000A and the mounting substrate can be improved particularly in the case of the side light emitting type. When the substrate is rectangular, the recess of the substrate may overlap with the recess on the short side of the substrate when viewed from above.

The maximum depth of each of the depressions in the Z direction is preferably 0.4 to 0.9 times the thickness of the substrate in the Z direction. When the depth of the recess is deeper than 0.4 times the thickness of the base material, the volume of the bonding member formed in the recess increases, so that the bonding strength between the light emitting device and the mounting substrate can be improved. Since the depth of the dent is shallower than 0.9 times the thickness of the base material, it is possible to suppress a decrease in the strength of the base material.

The light emitting device may include an insulating film 18 that covers a part of the second wiring 13. By providing the insulating film 18, it is possible to secure the insulating property on the lower surface and prevent a short circuit. In addition, it is possible to prevent the second wiring from being peeled off from the base material.

As in the light emitting device 1000C shown in FIG. 8, the second reflecting member 41 may be provided between the substrate 10 and the lower surface of the first light emitting element. By providing the second reflecting member 41, it is possible to suppress the light from the first light emitting element from being absorbed by the substrate. This improves the light extraction efficiency of the light emitting device. The second reflective member is also located between the substrate 10 and the lower surface of the second light emitting element. The second reflective member 41 is preferably in contact with the first reflective member. By doing so, it is possible to suppress the light from the light emitting element from being absorbed by the substrate. The second reflective member 41 covers the side surface of the convex portion of the first wiring. The upper surface of the second reflective member 41 is preferably located between the lower surface of the light emitting element and the upper surface of the light emitting element. By locating the upper surface of the second reflecting member 41 above the lower surface of the light emitting element, it is possible to suppress the light from the light emitting element from being absorbed by the electrodes of the light emitting element. Since the upper surface of the second reflecting member 41 is located above the lower surface of the light emitting element, it becomes easier to extract light from the side surface of the light emitting element, so that the light extraction efficiency of the light emitting device is improved. As the second reflective member, the same material as the first reflective member can be used. It is preferable that the base material of the first reflective member and the base material of the second reflective member are the same material. By doing so, the joint strength between the first reflective member and the second reflective member can be improved.

As shown in FIG. 8, a covering member 70 that covers the upper surface of the first light emitting element, the second light emitting element, and / or the third light emitting element may be provided. For example, the covering member 70 may include a diffusion member. By doing so, it is possible to reduce the light traveling in the Z direction and increase the light traveling in the X direction and / or the Y direction. As a result, the light from the light emitting element can be diffused in the light guide member, so that uneven brightness of the light emitting device can be suppressed. The covering member 70 is located between the upper surface of the light emitting element and the light guide member 50. The covering member 70 preferably exposes at least a part of the side surface of the light emitting element. By doing so, it is possible to suppress the reduction of light from the light emitting element traveling in the X direction and / or the Y direction.

The covering member 70 may include a wavelength conversion member. By doing so, the color adjustment of the light emitting device becomes easy. The wavelength conversion member included in the covering member 70 may be the same as or different from the wavelength conversion member included in the wavelength conversion layer. For example, when the peak wavelength of light emission of the light emitting element is in the range of 490 nm or more and 570 nm or less (wavelength range in the green region), the wavelength conversion member is a CASN-based phosphor excited by light in the range of 490 nm or more and 570 nm or less. / Or a SCASSN-based phosphor is preferable. Alternatively, a (Sr, Ca) _LiAl 3N ₄ : Eu phosphor may be used as the wavelength conversion member.

<Embodiment 2>
The light emitting devices 2000A and 2000B according to the second embodiment of the present invention will be described with reference to FIGS. 9 to 12. The light emitting device 2000A is different from the light emitting device 1000A according to the first embodiment in the recess, via, and the first reflective member included in the base material. The light emitting device 2000B differs from the light emitting device 1000A according to the first embodiment in the number of dents, vias, first reflecting member, and light emitting element provided in the base material.

As shown in FIGS. 10 and 11, when the substrate is rectangular in the top view, the recess 16 of the substrate can be separated from the recess on the short side of the substrate in the top view. By separating the recess 115 on the short side of the substrate and the recess 16 of the substrate, it is possible to reduce the portion where the thickness of the substrate is thin in the Z direction. This improves the strength of the base material. Further, in the top view, when the base material is rectangular, the first reflecting member 40 has a first reflecting portion 401 on the long side side and a second reflecting portion 402 on the short side side. When the recess 115 on the short side of the base material and the recess 16 of the base material are separated from each other, the second reflective portion 402 and the recess 16 of the base material are separated from each other in the top view. Further, the width of the second reflecting portion 402 may be longer than the width of the first reflecting member.

The number of light emitting elements is not particularly limited, and as shown in FIG. 12, two light emitting elements, a first light emitting element 20A and a second light emitting element 20B, may be provided. The light emitting device can be miniaturized by including only two light emitting elements, the first light emitting element 20A and the second light emitting element 20B.

Hereinafter, each component in the light emitting device according to the embodiment of the present invention will be described.

(Board 10)
The substrate 10 is a member on which a light emitting element is placed. The substrate 10 includes a base material 11 and a first wiring 12. The base material 11 is open to the upper surface of the base material and the side surface of the base material, and includes a recess surrounding the outer periphery of the upper surface of the base material. The base material 10 may further include a recess 16, a second wiring 13, a third wiring 14, and a via 15.

(Base material 11)
The base material 11 can be configured by using an insulating member such as a resin or a fiber reinforced resin, ceramics, or glass. Examples of the resin or fiber reinforced resin include epoxy, glass epoxy, bismaleimide triazine (BT), polyimide and the like. Further, the base material 11 may contain a white pigment such as titanium oxide. Examples of the ceramics include aluminum oxide, aluminum nitride, zirconium oxide, zirconium nitride, titanium oxide, titanium nitride, or a mixture thereof. Among these base materials, it is particularly preferable to use a base material having physical properties close to the coefficient of linear expansion of the light emitting element. The lower limit of the thickness of the base material can be appropriately selected, but from the viewpoint of the strength of the base material, it is preferably 0.05 mm or more, and more preferably 0.2 mm or more. Further, the upper limit of the thickness of the base material is preferably 0.5 mm or less, more preferably 0.4 mm or less, from the viewpoint of the thickness (depth) of the light emitting device.

(1st wiring 12)
The first wiring is arranged on the upper surface of the substrate and is electrically connected to the light emitting element. The first wiring can be made of copper, iron, nickel, tungsten, chromium, aluminum, silver, gold, titanium, palladium, rhodium, or alloys thereof. These metals or alloys may be single-layered or multi-layered. In particular, copper or a copper alloy is preferable from the viewpoint of heat dissipation. Further, even if the surface layer of the first wiring is provided with a layer of silver, platinum, aluminum, rhodium, gold or an alloy thereof from the viewpoint of wettability and / or light reflectivity of the conductive adhesive member. good.

(2nd wiring 13, 3rd wiring 14)
The second wiring is arranged on the lower surface of the substrate. The third wiring covers the inner wall of the recess and is electrically connected to the second wiring. For the second wiring and the third wiring, the same conductive member as the first wiring can be used.

(Beer 15)
The via 15 is provided in a hole penetrating the upper surface and the lower surface of the base material 11, and is a member that electrically connects the first wiring and the second wiring. The via 15 may be composed of a fourth wiring 151 that covers the surface of the through hole of the base material, and a filling member 152 that is filled in the fourth wiring 151. For the fourth wiring 151, the same conductive members as those of the first wiring, the second wiring, and the third wiring can be used. As the filling member 152, a conductive member or an insulating member may be used.

(Insulating film 18)
The insulating film 18 is a member for ensuring insulation on the lower surface and preventing a short circuit. The insulating film may be formed of any of those used in the art. For example, a thermosetting resin, a thermoplastic resin, or the like can be mentioned.

(1st light emitting element 20A, 2nd light emitting element 20B, 3rd light emitting element 20C)
The first light emitting element, the second light emitting element, and the third light emitting element are semiconductor elements that emit light by themselves by applying a voltage, and a known semiconductor element composed of a nitride semiconductor or the like can be applied. Examples of the first light emitting element, the second light emitting element, and the third light emitting element include an LED chip. The first light emitting element, the second light emitting element, and the third light emitting element include at least a semiconductor laminate, and in many cases, further include an element substrate. The top view shape of the first light emitting element, the second light emitting element, and the third light emitting element is preferably a rectangle, particularly a square shape or a rectangular shape long in one direction, but other shapes may be used, for example, a hexagon. If it has a shape, the luminous efficiency can be increased. The side surfaces of the first light emitting element, the second light emitting element, and the third light emitting element may be perpendicular to the upper surface, or may be inclined inward or outward. Further, the first light emitting element, the second light emitting element and the third light emitting element have positive and negative electrodes. The positive and negative electrodes can be composed of gold, silver, tin, platinum, rhodium, titanium, aluminum, tungsten, palladium, nickel or alloys thereof. The emission peak wavelength of the first light emitting element is 430 nm or more and less than 490 nm. The emission peak wavelength of the second light emitting element is 490 nm or more and 570 nm or less. As the semiconductor material, it is preferable to use a nitride semiconductor. Nitride semiconductors are mainly represented by the general formula In _x Al _y Ga _1-xy N (0 ≦ x, 0 ≦ y, x + y ≦ 1). In addition, InAlGaAs-based semiconductors, InAlGaP-based semiconductors, zinc sulfide, zinc selenide, silicon carbide and the like can also be used. The element substrates of the first light emitting element, the second light emitting element, and the third light emitting element are mainly crystal growth substrates capable of growing semiconductor crystals constituting the semiconductor laminate, but are semiconductor elements separated from the crystal growth substrate. It may be a bonding substrate to be bonded to the structure. Since the element substrate has translucency, it is easy to adopt flip-chip mounting, and it is easy to improve the light extraction efficiency. Examples of the base material of the element substrate include sapphire, gallium nitride, aluminum nitride, silicon, silicon carbide, gallium arsenic, gallium phosphorus, indium phosphorus, zinc sulfide, zinc oxide, zinc selenium, and diamond. Of these, sapphire is preferable. The thickness of the element substrate can be appropriately selected, for example, 0.02 mm or more and 1 mm or less, and preferably 0.05 mm or more and 0.3 mm or less from the viewpoint of the strength of the element substrate and / or the thickness of the light emitting device. ..

(Translucent member 30)
The translucent member is provided on the light emitting element and is a member that protects the light emitting element. The translucent member is composed of at least the following base materials. Further, the translucent member can function as a wavelength conversion member by containing the following wavelength conversion member in the base material. The base material of each layer of the translucent member is configured as follows. The base material of each layer may be the same or different. It is not essential that the translucent member has a wavelength conversion member.

(Base material of translucent member)
The base material of the translucent member may be any as long as it has translucency with respect to the light emitted from the light emitting element. In addition, "translucency" means that the light transmittance at the emission peak wavelength of the first light emitting element is preferably 60% or more, more preferably 70% or more, still more preferably 80% or more. Say that. As the base material of the translucent member, a silicone resin, an epoxy resin, a phenol resin, a polycarbonate resin, an acrylic resin, or a modified resin thereof can be used. It may be glass. Among them, silicone resin and modified silicone resin are excellent in heat resistance and light resistance, and are preferable. Specific examples of the silicone resin include dimethyl silicone resin, phenyl-methyl silicone resin, and diphenyl silicone resin. The translucent member can be configured by using one of these base materials in a single layer or by laminating two or more of these base materials. The "modified resin" in the present specification includes a hybrid resin. The base material of the translucent member includes a first diffusion layer, a translucent layer, a wavelength conversion layer, and a base material of a second diffusion layer.

The base material of the translucent member may contain various diffuse particles in the resin or glass. Examples of the diffused particles include silicon oxide, aluminum oxide, zirconium oxide, zinc oxide and the like. As the diffused particles, one of these can be used alone, or two or more of them can be used in combination. In particular, silicon oxide having a small coefficient of thermal expansion is preferable. Further, by using nanoparticles as diffusion particles, it is possible to increase the scattering of light emitted by the light emitting element and reduce the amount of the wavelength conversion member used. The nanoparticles are particles having a particle size of 1 nm or more and 100 nm or less. Further, the "particle size" in the present specification is defined by, for example, _D50 .

(Wavelength conversion member)
The wavelength conversion member absorbs at least a part of the primary light emitted by the light emitting element and emits secondary light having a wavelength different from that of the primary light. As the wavelength conversion member, one of the following specific examples can be used alone or in combination of two or more. When the translucent member includes a plurality of wavelength conversion layers, the wavelength conversion members contained in each wavelength conversion layer may be the same or different.

Examples of the wavelength conversion member that emits green light include yttrium _- aluminum-garnet-based phosphors (for example, Y3 (Al, Ga) ₅ O ₁₂ : Ce) and lutetium-aluminum-garnet-based phosphors (for example, Lu ₃ (Al, Ga)). ₅ O ₁₂ : Ce), terbium aluminum garnet fluorescent material (for example, Tb ₃ (Al, Ga) ₅ O ₁₂ : Ce) fluorescent material, silicate fluorescent material (for example, (Ba, Sr) ₂ SiO ₄ : Eu ), Chlorosilicate-based fluorescent material (for example, Ca ₈ Mg (SiO ₄ ) ₄ Cl ₂ : Eu), β-sialon-based fluorescent material (for example, Si _6-z Al _{z Oz} N _8-z : Eu (0 <z <4). .2)), SGS-based fluorescent material (for example, SrGa ₂ S ₄ : Eu) and the like. As the wavelength conversion member for yellow emission, an α-sialon-based phosphor (for example, M _z (Si, Al) ₁₂ (O, N) ₁₆ (where 0 <z ≦ 2), M is Li, Mg, Ca, Y. , And lanthanide elements other than La and Ce). In addition, among the wavelength conversion members that emit green light, there is also a wavelength conversion member that emits yellow light. By substituting a part of Y with Gd, the emission peak wavelength can be shifted to the long wavelength side, and yellow emission is possible. In addition, among these, a wavelength conversion member capable of orange emission is also included. Examples of the wavelength conversion member that emits red light include nitrogen-containing calcium aluminosilicate (CASN or SCASN) -based phosphors (for example, (Sr, Ca) AlSiN ₃ : Eu), and manganese-activated fluoride-based fluorescence. It is a phosphor represented by a body (general formula (I) A ₂ [M _1-a Mn _a F ₆ ] (however, in the above general formula (I), A is K, Li, Na, Rb, Cs. And at least one element selected from the group consisting of NH4, M is at least one element selected from the group consisting of Group ₄ elements and Group 14 elements, and a is 0 <a <0.2. (Satisfying))). As a typical example of this manganese-activated fluoride-based phosphor, there is a phosphor of manganese _- activated potassium fluoride silicate (for example, K2 SiF ₆ : Mn).

(First reflective member)
From the viewpoint of light extraction efficiency in the Z direction, the first reflecting member preferably has a light reflectance of 70% or more, more preferably 80% or more at the emission peak wavelength of the first light emitting element. It is even more preferable that it is 90% or more. Further, the first reflective member is preferably white. Therefore, it is preferable that the first reflective member contains a white pigment in the base material. The first reflective member goes through a liquid state before being cured. The first reflective member can be formed by transfer molding, injection molding, compression molding, potting, or the like.

(Base material of the first reflective member)
A resin can be used as the base material of the first reflective member, and examples thereof include silicone resin, epoxy resin, phenol resin, polycarbonate resin, acrylic resin, and modified resins thereof. Among them, silicone resin and modified silicone resin are excellent in heat resistance and light resistance, and are preferable. Specific examples of the silicone resin include dimethyl silicone resin, phenyl-methyl silicone resin, and diphenyl silicone resin.

(White pigment)
White pigments include titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, magnesium silicate, barium titanate, barium sulfate, aluminum hydroxide, aluminum oxide, zirconium oxide, One of the silicon oxides can be used alone or in combination of two or more of them. The shape of the white pigment can be appropriately selected and may be amorphous or crushed, but spherical is preferable from the viewpoint of fluidity. The particle size of the white pigment is, for example, about 0.1 μm or more and 0.5 μm or less, but the smaller the particle size is preferable in order to enhance the effect of light reflection and coating. The content of the white pigment in the light-reflecting reflective member can be appropriately selected, but from the viewpoint of light reflectivity and viscosity in the liquid state, for example, it is preferably 10 wt% or more and 80 wt% or less, and 20 wt% or more and 70 wt% or less. More preferably, 30 wt% or more and 60 wt% or less are even more preferable. In addition, "wt%" is a weight percent, and represents the ratio of the weight of the material to the total weight of the light-reflecting reflective member.

(Second reflective member)
The second reflective member is a member located between the light emitting element and the substrate. As the second reflective member, the same reflective member as the first reflective member can be used.

(Coating member 70)
The covering member covers the light extraction surface of the light emitting element, diffuses the light of the light emitting element, or converts the light of the light emitting element into light having a peak wavelength different from the light of the peak wavelength of the light emitting element.

(Base material of covering member)
As the base material of the covering member, the same material as the base material of the translucent member can be used.

(Diffuse particles of covering member)
As the diffusing particles of the covering member, the same material as the diffusing particles of the translucent member can be used.

(Light guide member 50)
The light guide member is a member that covers the upper surface of the light emitting element and the base material. Examples of the base material of the light guide member include silicone resin, epoxy resin, phenol resin, polycarbonate resin, acrylic resin, and modified resins thereof. Among them, silicone resin and modified silicone resin are excellent in heat resistance and light resistance, and are preferable. Specific examples of the silicone resin include dimethyl silicone resin, phenyl-methyl silicone resin, and diphenyl silicone resin. Further, the base material of the light guide member may contain the same filler as the above-mentioned translucent member.

(Conductive adhesive member 60)
The conductive adhesive member is a member that electrically connects the electrode of the light emitting element and the first wiring. Conductive adhesive members include bumps such as gold, silver and copper, metal powders such as silver, gold, copper, platinum, aluminum and palladium and metal pastes containing resin binders, tin-bismuth-based, tin-copper-based and tin. -Any one of silver-based, gold-tin-based solder, and low melting point metal and other brazing materials can be used.

The light emitting device according to the embodiment of the present invention includes a backlight device for a liquid crystal display, various lighting fixtures, a large display, various display devices such as advertisements and destination guides, a projector device, a digital video camera, a facsimile, and a copier. , Can be used as an image reading device in a scanner or the like.

1000A, 1000B, 1000C, 2000A, 2000B Light emitting device 10 Substrate 11 Substrate
115 Recess 12 1st wiring 13 2nd wiring 14 3rd wiring 15 vias
151 4th wiring
152 Filling member 16 Indentation 18 Insulation film 20A 1st light emitting element 20B 2nd light emitting element 20C 3rd light emitting element 30 Translucent member 40 1st reflective member 41 2nd reflective member 50 Light guide member 60 Conductive adhesive member

Claims (9)

A substrate including an upper surface , a lower surface located on the opposite side of the upper surface, a substrate having a side surface located between the upper surface and the lower surface, and a first wiring arranged on the upper surface . The substrate has a recess that opens into the upper surface and the side surface and surrounds the outer periphery of the upper surface .
A first light emitting element having an emission peak wavelength of 430 nm or more and less than 490 nm, which is electrically connected to the first wiring and is placed on the first wiring.
A second light emitting element having an emission peak wavelength of 490 nm or more and 570 nm or less, which is electrically connected to the first wiring and is placed on the first wiring.
A light guide member that covers the first light emitting element, the second light emitting element, and the upper surface and is separated from the recess.
An annular first reflective member arranged in the recess, surrounding the upper surface and the light guide member, and in contact with the light guide member,
Equipped with
In top view, each of the substrate, the first light emitting element, and the second light emitting element has a rectangular shape.
The rectangular long side of the substrate extends along the first direction.
The first light emitting element and the second light emitting element are arranged side by side in the first direction.
One of the rectangular short sides of the first light emitting element faces one of the rectangular short sides of the second light emitting element.
A light emitting device in which at least a part of the side surface of the base material and at least a part of the outer surface of the first reflective member are flush with each other. Further equipped with a translucent member,
The light emitting device according to claim 1 , wherein the translucent member covers the upper surface of the first light emitting element and the upper surface of the second light emitting element via the light guide member. The light emitting device according to claim 2 , wherein the translucent member includes a wavelength conversion member. The translucent member is
The first diffusion layer and
The translucent layer arranged on the first diffusion layer and
The wavelength conversion layer arranged on the translucent layer and
The second diffusion layer arranged on the wavelength conversion layer and
The light emitting device according to claim 3. The first reflective member is
The first reflective portion on the long side of the rectangular shape of the substrate and
The second reflective portion on the short side of the rectangular shape of the substrate ,
Have,
The light emitting device according to any one of claims 1 to 4 , wherein the width of the first reflecting portion is larger than the width of the second reflecting portion in a top view . The substrate has recesses that open into the lower surface and the side surface.
The light emitting device according to claim 5 , wherein the second reflecting portion is separated from the recess in a top view. The light emitting device according to any one of claims 1 to 6 , wherein the width of the first reflective member in a top view is 10 μm or more and 50 μm or less. The light emitting device according to any one of claims 1 to 7 , further comprising a second reflecting member located between the substrate and the lower surface of the first light emitting element. Further, a third light emitting element arranged side by side with the first light emitting element and the second light emitting element in the first direction is further provided.
The light emitting device according to any one of claims 1 to 8, wherein the light emitting peak wavelength of the third light emitting element is the same as the light emitting peak wavelength of the first light emitting element.

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